The antifungal eugenol perturbs dual aromatic and branched-chain amino acid permeases in the cytoplasmic membrane of yeast

PLoS One. 2013 Oct 18;8(10):e76028. doi: 10.1371/journal.pone.0076028. eCollection 2013.


Eugenol is an aromatic component of clove oil that has therapeutic potential as an antifungal drug, although its mode of action and precise cellular target(s) remain ambiguous. To address this knowledge gap, a chemical-genetic profile analysis of eugenol was done using ∼4700 haploid Saccharomyces cerevisiae gene deletion mutants to reveal 21 deletion mutants with the greatest degree of susceptibility. Cellular roles of deleted genes in the most susceptible mutants indicate that the main targets for eugenol include pathways involved in biosynthesis and transport of aromatic and branched-chain amino acids. Follow-up analyses showed inhibitory effects of eugenol on amino acid permeases in the yeast cytoplasmic membrane. Furthermore, phenotypic suppression analysis revealed that eugenol interferes with two permeases, Tat1p and Gap1p, which are both involved in dual transport of aromatic and branched-chain amino acids through the yeast cytoplasmic membrane. Perturbation of cytoplasmic permeases represents a novel antifungal target and may explain previous observations that exposure to eugenol results in leakage of cell contents. Eugenol exposure may also contribute to amino acid starvation and thus holds promise as an anticancer therapeutic drug. Finally, this study provides further evidence of the usefulness of the yeast Gene Deletion Array approach in uncovering the mode of action of natural health products.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Transport Systems / antagonists & inhibitors*
  • Amino Acids, Aromatic / metabolism*
  • Amino Acids, Branched-Chain / metabolism*
  • Antifungal Agents / pharmacology*
  • Cell Membrane / metabolism*
  • Eugenol / pharmacology*
  • Gene Deletion
  • Metabolic Networks and Pathways / drug effects
  • Phenotype
  • Protein Biosynthesis / drug effects
  • Saccharomyces cerevisiae / drug effects
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / metabolism
  • Yeasts / drug effects*
  • Yeasts / genetics
  • Yeasts / metabolism*


  • Amino Acid Transport Systems
  • Amino Acids, Aromatic
  • Amino Acids, Branched-Chain
  • Antifungal Agents
  • Eugenol

Grant support

Funding was from Natural Sciences and Engineering Research Council of Canada to AG and MLS; Ministry of Science, Research and Technology, Iran to ED. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.